1. Field of the Invention
The present invention relates to a printed circuit module, consisting of a printed circuitboard equipped with electrical modules, a connector part comprising a plurality of contact elements, and a pressure part exerting a pressure on a printed circuitboard surface, for example a cooling device.
2. Description of the Prior Art
In the construction of large electronic systems, such as for example, data processing systems, the object is to obtain signal lines which are as short as possible and having a defined wave resistance, and, hence, obtaining high switching speeds. This can be achieved with the aid of printed circuit modules which exhibit single or multi-layer printed circuitboards having integrated modules and which are connected via electrical conductors to a wiring plate. In order to obtain a high conductor density, the latter is likewise executed in multilayer fashion and contains signal lines for the connection of assemblies with one another, as well as potential lines and apply lines. In the case of printed circuit modules of maximum packing density, the numerous external connections necessary for this purpose are distributed over the narrowest space on the lower side, in order to directly establish the connection to the printed circuitboard.
From the U.S. Pat. No. 3,993,123, a printed circuit module having heat-emitting modules is known which are contacted on one side of the support plate. They are disposed beneath the cooling device which surrounds the modules like a cap from which one or more spring parts press a heat dissipating element on each module. The pressure produced, therefore, is diverted to the plate edges which are flanged onto the cooling device, whereby, however, the support can undergo warping.
Since also a large number of perpendicularly-projecting connectors is mounted on the support plate, a warping impairs the plugging and unplugging of the printed circuit modules which, as is known, requires pins which are precisely aligned relative to one another. On the other hand, the danger exists that pins will become bent or broken and that faulty connections thereby result, or that at least even greater mating and drawing forces need be applied than are necessary anyway because of the large number of connections. Moreover, in the case of the printed circuitboard avoiding mechanical tension, the danger exists that fine cracks will result in the printed circuitboards and interrupt the connections. This can occur or the more readily when the pins are fixedly connected to the printed circuitboard and the already existing deflection during frequent change of the printed circuit module is increased due to tensile or forces, on the one hand, and is again reset due to the flexibility of the printed circuitboard, on the other hand, which can lead to a fatigue of the printed conductor material.